Gas liberating devices



June 25, 1963 E. c. FlLsTRuP GAS LIBERATING DEVICES Filed Nov. 10. 1960 /mm/mm/vmdmwmm E A/m// on Q @V INVENTOR EDWARD C. FILSTRUF zy l n z United States Patent O 3,094,931 GAS LIBERATIN G DEVICES Edward Christian Filstrup, St. Joseph, Mich., assignor to lin Mathieson Chemical Corporation, East Alton, Ill.,

a corporation of Virginia Filed Nov. 10, 1960, Ser. No. 68,537 4 Claims. (Cl. 102-25) This invention relates to gas liberating devices and more particularly to such `devices adapted to effect the sudden release of compressed gas to serve as a work performing medium. While such devices are applicable Ytomany commercial applications, the present invention will be described with particular 4reference to blasting cartridges utilizing .a vgas under pressure.

Material breaking cartridges using compressed gas to execute the required work are well known and lwidely used in the min-ing industry. Such cartridges 4or blasting devices are all reliant upon the sudden release of compressed -gas to give `a quasi explosive effect. 'The predecessors of this type Aof blasting cartridges consisted essentially `of a cylindrical gas containing cartridge having venting means. The cartridges were charged with gas under considerable pressure, sealed and then conveyed to the face to be worked. The compressed gas within these cartridges was released by elaborate remote control means. More recently, the practice has been to place an uncharged cartridge in the bore hole :and pump gas through a suitable conduit into the cartridge in situ. Conventionally, these cartridges are lformed of high strength materials and are provided with a relatively weak member which shears or ruptures so as to liberate the charge of gas from the cartridge body at a predetermined discharge pressure. Such cartridges are generally satisfactory but have a number of inherent disadvantages. Foremost among these are the diiiiculty in accurately controlling discharge pressures and the necessary manipulation of .the shell after each discharge.

These shortcomings have been well recognized and have led to a concerted effort for the development of automatic or semi-.automatic shells. While many shells of this type have been presented, they have met with only a modicum of success. The previous types of automatic cartridges are operable, `but they are very heavy, complex and unreliable. Although the expendable portions iof the shell have been eliminated, this elimination has introduced new and more serious problems. Normally, the known automatic shells rely upon a multiplicty of moving parts to initiate the main release valve. Such complexity cf design led to cartridges that are difficult to control and exceedingly diiiicult to discharge :at a desi-red predetermined pressure.

Theerfore, it is an object of this invention to provide new and improved `automatic and semi-automatic material breaking devices utilizing compressed gas. A further object is to provide devices `of this character having novel gas release control means. Another object cf this invention is to provide simplified `automatic and semi-automatic shells overcoming the disadvantages of the prior art. It is `also an object of this invention to provide improved automatic and semi-automatic gas operated devices that are easily discharged at `diiiering pressures.

The manner in which these and other objects are accomplished will be apparent from the following specification together with the drawing in which:

FIGURE 1 is a longitudinal sectional view of a blasting device illustrating an embodiment ot the present i11- vention; and

FIGURE 2 is a longitudinal sectional view of a blast- 'i ing device illustrating another embodiment ci the present invention.

As shown in FIGURE l of the drawing, a blasting cartridge is provided with an elongated tubular body 1 formed cf metal or equivalent material suiiiciently strong to contain gas under high pressures, between about 6,000 and 20,000 pounds per square inch. Suitable means 2 are provided at one end for introducing compressed -gas into the cartridge. The diameter of the cartridge is such that it may be freely set within a bore drilled in the face of the material to be mined. That end of the body remote from the gas inlet is screw-threadedly lattached to an adaptor 3 4as indicated at 4, the seal between Athe body and the adaptor being completed by O-ring 5. The endof the adaptor remote from the body terminates in an internally threaded portion `6, by means of which it i-s connected to end cap 7. The joint between the end cap and the adaptor is sealed by means of resilient O-ring 8. The adaptor 2 is provided with a plurality Iof discharge ports 9 which are normally spanned and sealed by sleeve valve 10. The valve is slidable within the adaptor and is in sealing relationship therewith by means of resilient O-ring 11. The valve forms a metal-to-metal .seal with follower ring 12. This follower ring is also slidable within adaptor 3, but is restrained in its movement by the end of ybody 1 which it abuts and by shoulder 13 on adaptor 3. The seal between follower ring 12 and adaptor 3 is maintained by resilient O-ring 14.

Stem 1S is rigidly secured to valve 10 and extends into channel 16 of end cap 7. I'f desired, channel 16 may be provided `with vent 38 to prevent any undue pressure build-up in this area. As shown in the drawing, the stem passes through the base `of valve 1i) and is secured to the valve by nut 17. It will be readily appreciated, however, that the valve and stem can be secured in any convenient fashion or may be a unitary member. Passagew-ays 18 through valve 10 insure uniformity ot pressure in chambers 19 and 20 on either side yof the valve. A sliding seal between end cap 7 and stem 15 is maintained by `one or more resilient 0-rings 21. In this embodiment, the end cap is provided with metallic bushing 22 to provide 4ready access to the O-rings. A portion 23 oi the end of stem 15 is beveled and adapted to contact cylinder or trigger 24. This trigger is slidable `at substantially right angles to the stem and its sealing relationship with the end cap is maintained by O-ring 25. Spring 26 normally urges the trigger 24 into locked engagement with stem 15. A passageway 27 provides communication `between chamber 20 and spring chamber 28 located between trigger 24 and screw plug 29, the screw plug being provided with Aan O-ring 30.

Channel 31 passes from spring chamber 28 to valve chamber 32 which is normally closed by ball valve 33 due to the action of spring 34. The tension of spring 34 is readliy adjustable by screw-threaded pressure-setting plug 35. This plug is provided with a channel 36 to the atmosphere. This channel and channel 31 have effective cross-sectional tareas substantially greater than the eiiective cross-sectional area of passageway 27.

In operation, compressed gas is introduced through gas inlet 2 into chamber 19. AIt readily passes through passageways `18 in valve 10 into chamber 20` and at a somewhat reduced rate through passageway 27 into spring chamber 28. The gas also passes through channel 31 and exerts a force against ball valve 33. Thus, the gas pressure within spring chamber 28 cooperates with spring 26 to maintain trigger 24 in locking relationship with stem 15.

As the gas pressure is increased, valve 10 and stem y15 are urged to the right in opposition to the action of spring 37. This tendency of the valve and stem to move to the right is a result of their having a lesser elective cross-sectional area on the right than on the left. Likewise, metallic follower ring is urged t the right since it too has a greater effective cross-sectional area on its left than onAits right hand end. With both the valve and follower ring 12 being urged to the right as the pressure is increased, the maintenance of the metal-to-metal seal between these members is insured until the time of discharge.

The introduction of compressed air into the cartridge -is continued until the pressure in channel 31 is ,sufficient to unseat ball valve 33 in opposition to the force exerted upon it by spring 34. When the ball valve is slightly unseated the effective area of the valve exposed to the pressure within the cartridge is suddenly increased. This insures rapid opening of the valve with Ian immediate reduction of pressure in `spring chamber 28. Although compressed gas will continue .to enter spring chamber 28 through passageway ,27, the pressure in the spring chamber is rapidly reduced because the diameters of channels 31 and 36 are much greater than the diameter of passageway 27. With the venting of spring chamber 28, the pressure acting `on valve 10 is suicient to move stem 15 to the right and thus depress trigger 24. The angle between the longitudinal axis of stem 15 `and its beveled portion 23 must be sufciently small to insure movement of trigger 24 -in response to force applied by stem -15 coupled with a reduction in pressure lin spring chamber 28. With the trigger thus unlocked, valve v10 is free to move to the rig-ht. This movement results in a rapid opening of ports -9 and an efficient discharge of the gas contained within chambers 19 and 20.

After the charge of gas is expelled from chamber 19, valve 10v and follower ring 12 are returned to their normal sealing position as shown in FIGU-RE l. Also, trigger 24 resumes its locking position by the action of spring 26 and ball valve 33 is reseated by valve spring 34. The cartridge is thus automatically returned to condition for recharging.

The cartridge of FIGURE 2 is a semi-.automatic shell but relies for :its operation upon the same principles as described above in connection with FIGURE l. A number of the components of this second embodiment are substantia-lly the same as the corresponding components of FIGURE l and are thus Iidentiiied by the same reference numerals.

Valve 10, stem 1-5 and follower ringV 12 are substantially the same as those previously described in the lirst embodiment. Also, trigger 24 and ball valve 33 are for all practical purposes ident-ical to those described in FIGURE y1.

Gas inlet 2 is connected with pipe 39 terminating in spider-type xtu-re 40. The end of pipe 39 is preferably provided with a tapering screw-threaded section 41 to facilitate securing it to the fixture. Passageway 42 extends through iixture 40 and into communication with channel 43, passing lengthwise through the wall of adaptor 3. The opposite end of channel 43 communicates with passageway 144 in end cap 7. In order to insure mating of channel 43 with passageways 42 and 44, either channel 43 or the other passageways can terminate in an annular ring (not shown) at their point of juncture. Passageway 4'5 serves to connect passageway 44 with spring chamber 28. For ease of manufacture, passageway 45 extends beyond its juncture with passageway 44 as` shown at 46 and .the end thereof is plugged at 47 in any convenient manner. It will be noted that p-assageway 42 is provided on either :side fwith 0-rings 48 and 49 and that passageway 44 is likewise provided with aA pair of YOV-rings 50 and 51, to prevent any leakage of airtfrom these passageways at their point of juncture 'with channel 43. Passageway 59 extends from valve chamber 28 to transverse passageway 52. This latter pasageway extends to the surface of end cap 7 andV is plugged as shown at 53. Passageway 52 thus serves as a means of communication between passageway 59 and passageway S4. Bushing 22 isA provided with aperture 55. v I

In the operation of the cartridge of this embodiment, feed valve `56 is opened and bleed valve `57 is maintained in a closed position. Thus the compressed gas is passed through line 58 into -gas inlet 2. The lgas then passes through pipe 39 and lis conducted to channel 43 by passageway 42. From `channel 43 it enters passageways 44 and 45 .and thence into spring chamber 28 so `as to exert' -a locking pressure on trigger 24. From spring chamber 28, the gas passes through passageways 59, 52, and 54 and exerts unseating pressure on ball valve 33. With the bal-l valve unseated, the gas is then free to enter chambers 19 Iand 2.0r through spring chamber 32 and aperture l55 in bushing 22.

Valve 56 is maintained open and valve 5-7 kept closed until the desired discharge pressure is attained Within the cartridge. As described in connection with the embodiment of FIGURE l, bot-h valve 10 and follower ring 12 Iare urged to the right by gas pressure within the cartridge. Also, trigger 24 isheld in a locked position by the pressure within spring chamber 28 augmented by spring 26. When the predetermined discharge pressure has been built up within the cartridge, -feed valve 56 is closed and bleed valve 57 is opened. This results in a reduction of pressure within channel 43 and the passageways in cornm-unication with it including passageway 54. With the pressure reduced on the right band side of ball valve 33, the pressure within spring chamber 32 together with spring 34 causes the valve toclose. This eliminates any possibility cf venting chambers 19 an-d YZO.

With this reduction in pressure, the force of the gas in spring chamber 28 is insuflicient to maintain trigger 24 in a locked position. Thus, trigger 24 is forced up- Y wardly by stem 15 permitting the gas pressure within the cartridge to force valve 10 to the right and away from ports 9. rIlhe compressed gas within the cartridge is then liberated in substantially the same manner as described hereinbefore. When the gas within the cartridge has been expelled, the shell is returned to condition for recharging by the action of springs 37 and 26.

-While the invention has been described with particular reference to blasting or coal breaking cartridges, it will be readily appreciated that it is also applicable to any pressure release device in which a charge of compressed gas is suddenly liberated to act as a work performing medium. Such devices include metal Working and shaping devices, cutting devices, power cartridges, safety valves, .and the like.

Although the invention has been described in considerable detail in the yforegoing for the purpose of illustration, it is to be under-stood that such detail is solely Ifor that purpose and that many modifications can be made without departing from the spirit and scope of the invention.

i What is claimed is:

1. A device for liberating a charge of compressed gas comprising a substantially cylindrical body,

means for introducing gas under pressure into one end ofthe body,

a discharge head located proximate the opposite end of the body,

a lateral discharge port,

a pressure-responsive Valve normally closing and spanning said port, said gas pressure tending to urge said valve to an open position,

ak stem having ya bevel portion rigidly connected to the valve and extending therefrom toward the discharge head,

trigger means operable to engage the bevel portion portion of said stem normally blocking movement of the stem land the valve toward the discharge head,

said trigger means being held in'restraining position by gas pressure within the body,

and valve means -for reducing the gas pressure on the .trigger means whereby the pressure on the valve is operative to drive the stem axially causing the stem to cam the trigger means out of blocking position.

2. The device of claim 1 in which the valve means for reducing pressure on the restraining means `is internally controlled.

3. The device of claim 1 in which the valve means for reducing pressure on the restraining means is eX- ternally controlled,

4. A device for liberating a charge of compressed gas comprising a substantially cylindrical body,

a gas receiving chamber Within the body,

means `for introducing gas under pressure into one end of the body,

an end cap closing the end of the body remote from the inlet,

a longitudinal channel passing through a portion of the end cap,

a transverse channel intersecting the longitudinal channel and disposed generally normal thereto,

a lateral discharge port,

`a pressure responsive valve norm-ally closing and spanning said port,

a stern having a bevel portion rigidly connected to the valve and extending therefrom into one end of the longitudinal channel,

the stem being slidable Within the channel,

a pressure responsive trigger slidable in the transverse channel and Operable to engage said bevel portion,

resilient means urging the trigger toward the stem whereby said stem is blocked,

means of communication between the chamber and the transverse channel independent of said longitudinal channel for introducing gas pressure to said gas receiving chamber and for applying gas pressure to said trigger, valve means for reducing gas pressure in said means of communication,

said means of communication including a conduit for directing compressed gas from said means for introducing gas to said transverse channel and from said transverse channel to said gas receiving chamber, a poppet valve mounted in said means of cornmunication between said gas receiving Chamber and the transverse channel operative to retain pressure in said chamber when the gas pressure in said means of communication is reduced whereby the trigger isV driven by the stem out of blocked position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,435,116 Armstrong Ian. 27, 1948 2,720,170 Hesson et al. Oct. 1l, 1955 3,041,970 Foster July 3, 1962 

1. A DEVICE FOR LIBERATING A CHARGE OF COMPRESSED GAS COMPRISING A SUBSTANTIALLY CYLINDRICAL BODY, MEANS FOR INTRODUCING GAS UNDER PRESSURE INTO ONE END OF THE BODY, A DISCHARGE HEAD LOCATED PROXIMATE THE OPPOSITE END OF THE BODY, A LATERAL DISCHARGE PORT, A PRESSURE-RESPONSIVE VALVE NORMALLY CLOSING AND SPANNING SAID PORT, SAID GAS PRESSURE TENDING TO URGE SAID VALVE TO AN OPEN POSITION, A STEM HAVING A BEVEL PORTION RIGIDLY CONNECTED TO THE VALVE AND EXTENDING THEREFROM TOWARD THE DISCHARGE HEAD, TRIGGER MEANS OPERABLE TO ENGAGE THE BEVEL PORTION PORTION OF SAID STEM NORMALLY BLOCKING MOVEMENT OF THE STEM AND THE VALVE TOWARD THE DISCHARGE HEAD, SAID TRIGGER MEANS BEING HELD IN RESTRAINING POSITION BY GAS PRESSURE WITHIN THE BODY, AND VALVE MEANS FOR REDUCING THE GAS PRESSURE ON THE TRIGGER MEANS WHEREBY THE PRESSURE ON THE VALVE IS OPERATIVE TO DRIVE THE STEM AXIALLY CAUSING THE STEM TO CAM THE TRIGGER MEANS OUT OF BLOCKING POSITION. 